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author | Mickaël Salaün <mic@linux.microsoft.com> | 2021-04-22 18:41:20 +0300 |
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committer | James Morris <jamorris@linux.microsoft.com> | 2021-04-22 22:22:11 +0300 |
commit | e1199815b47be83346c03e20a3de76f934e4bb34 (patch) | |
tree | e71d6716f8d7d3aa57a7f179e931276bc5027524 /tools/testing/selftests/landlock/common.h | |
parent | 265885daf3e5082eb9f6e2a23bdbf9ba4456a21b (diff) | |
download | linux-e1199815b47be83346c03e20a3de76f934e4bb34.tar.xz |
selftests/landlock: Add user space tests
Test all Landlock system calls, ptrace hooks semantic and filesystem
access-control with multiple layouts.
Test coverage for security/landlock/ is 93.6% of lines. The code not
covered only deals with internal kernel errors (e.g. memory allocation)
and race conditions.
Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Vincent Dagonneau <vincent.dagonneau@ssi.gouv.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-11-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
Diffstat (limited to 'tools/testing/selftests/landlock/common.h')
-rw-r--r-- | tools/testing/selftests/landlock/common.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h new file mode 100644 index 000000000000..20e2a9286d71 --- /dev/null +++ b/tools/testing/selftests/landlock/common.h @@ -0,0 +1,183 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Landlock test helpers + * + * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> + * Copyright © 2019-2020 ANSSI + * Copyright © 2021 Microsoft Corporation + */ + +#include <errno.h> +#include <linux/landlock.h> +#include <sys/capability.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "../kselftest_harness.h" + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +/* + * TEST_F_FORK() is useful when a test drop privileges but the corresponding + * FIXTURE_TEARDOWN() requires them (e.g. to remove files from a directory + * where write actions are denied). For convenience, FIXTURE_TEARDOWN() is + * also called when the test failed, but not when FIXTURE_SETUP() failed. For + * this to be possible, we must not call abort() but instead exit smoothly + * (hence the step print). + */ +#define TEST_F_FORK(fixture_name, test_name) \ + static void fixture_name##_##test_name##_child( \ + struct __test_metadata *_metadata, \ + FIXTURE_DATA(fixture_name) *self, \ + const FIXTURE_VARIANT(fixture_name) *variant); \ + TEST_F(fixture_name, test_name) \ + { \ + int status; \ + const pid_t child = fork(); \ + if (child < 0) \ + abort(); \ + if (child == 0) { \ + _metadata->no_print = 1; \ + fixture_name##_##test_name##_child(_metadata, self, variant); \ + if (_metadata->skip) \ + _exit(255); \ + if (_metadata->passed) \ + _exit(0); \ + _exit(_metadata->step); \ + } \ + if (child != waitpid(child, &status, 0)) \ + abort(); \ + if (WIFSIGNALED(status) || !WIFEXITED(status)) { \ + _metadata->passed = 0; \ + _metadata->step = 1; \ + return; \ + } \ + switch (WEXITSTATUS(status)) { \ + case 0: \ + _metadata->passed = 1; \ + break; \ + case 255: \ + _metadata->passed = 1; \ + _metadata->skip = 1; \ + break; \ + default: \ + _metadata->passed = 0; \ + _metadata->step = WEXITSTATUS(status); \ + break; \ + } \ + } \ + static void fixture_name##_##test_name##_child( \ + struct __test_metadata __attribute__((unused)) *_metadata, \ + FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \ + const FIXTURE_VARIANT(fixture_name) \ + __attribute__((unused)) *variant) + +#ifndef landlock_create_ruleset +static inline int landlock_create_ruleset( + const struct landlock_ruleset_attr *const attr, + const size_t size, const __u32 flags) +{ + return syscall(__NR_landlock_create_ruleset, attr, size, flags); +} +#endif + +#ifndef landlock_add_rule +static inline int landlock_add_rule(const int ruleset_fd, + const enum landlock_rule_type rule_type, + const void *const rule_attr, const __u32 flags) +{ + return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, + rule_attr, flags); +} +#endif + +#ifndef landlock_restrict_self +static inline int landlock_restrict_self(const int ruleset_fd, + const __u32 flags) +{ + return syscall(__NR_landlock_restrict_self, ruleset_fd, flags); +} +#endif + +static void _init_caps(struct __test_metadata *const _metadata, bool drop_all) +{ + cap_t cap_p; + /* Only these three capabilities are useful for the tests. */ + const cap_value_t caps[] = { + CAP_DAC_OVERRIDE, + CAP_MKNOD, + CAP_SYS_ADMIN, + CAP_SYS_CHROOT, + }; + + cap_p = cap_get_proc(); + EXPECT_NE(NULL, cap_p) { + TH_LOG("Failed to cap_get_proc: %s", strerror(errno)); + } + EXPECT_NE(-1, cap_clear(cap_p)) { + TH_LOG("Failed to cap_clear: %s", strerror(errno)); + } + if (!drop_all) { + EXPECT_NE(-1, cap_set_flag(cap_p, CAP_PERMITTED, + ARRAY_SIZE(caps), caps, CAP_SET)) { + TH_LOG("Failed to cap_set_flag: %s", strerror(errno)); + } + } + EXPECT_NE(-1, cap_set_proc(cap_p)) { + TH_LOG("Failed to cap_set_proc: %s", strerror(errno)); + } + EXPECT_NE(-1, cap_free(cap_p)) { + TH_LOG("Failed to cap_free: %s", strerror(errno)); + } +} + +/* We cannot put such helpers in a library because of kselftest_harness.h . */ +__attribute__((__unused__)) +static void disable_caps(struct __test_metadata *const _metadata) +{ + _init_caps(_metadata, false); +} + +__attribute__((__unused__)) +static void drop_caps(struct __test_metadata *const _metadata) +{ + _init_caps(_metadata, true); +} + +static void _effective_cap(struct __test_metadata *const _metadata, + const cap_value_t caps, const cap_flag_value_t value) +{ + cap_t cap_p; + + cap_p = cap_get_proc(); + EXPECT_NE(NULL, cap_p) { + TH_LOG("Failed to cap_get_proc: %s", strerror(errno)); + } + EXPECT_NE(-1, cap_set_flag(cap_p, CAP_EFFECTIVE, 1, &caps, value)) { + TH_LOG("Failed to cap_set_flag: %s", strerror(errno)); + } + EXPECT_NE(-1, cap_set_proc(cap_p)) { + TH_LOG("Failed to cap_set_proc: %s", strerror(errno)); + } + EXPECT_NE(-1, cap_free(cap_p)) { + TH_LOG("Failed to cap_free: %s", strerror(errno)); + } +} + +__attribute__((__unused__)) +static void set_cap(struct __test_metadata *const _metadata, + const cap_value_t caps) +{ + _effective_cap(_metadata, caps, CAP_SET); +} + +__attribute__((__unused__)) +static void clear_cap(struct __test_metadata *const _metadata, + const cap_value_t caps) +{ + _effective_cap(_metadata, caps, CAP_CLEAR); +} |